The present invention relates to methods and apparatus for analyzing machine lubrication oil.
Lubrication oil circulated through the bearings, pins and sliders of an operating machine both effects and reflects the machine condition. By the size, shape, density and magnetic responsiveness of particles suspended or mixed within the lubrication oil, substantial conclusions may be drawn or inferred about the state of machine wear, the rate of such wear and in some cases, the identity of the particular component yielding such wear or degradation.
Although it is known to magnetically separate iron wear particles from a machine lube oil sample, the viscosity of such oil is usually sufficiently high to retard separation even in the presence of a magnetic field. Extremely small, non-magnetic metal particles such as brass, copper and aluminum are extremely slow to settle under gravity forces alone. Low density non-magnetic particles such as soot and silica may remain buoyantly suspended.
It is also known to separate such particles by diluting an oil sample with solvent to lower the viscosity and then filter separating suspended particles from the diluted sample. However, this procedure leaves all the separated particles in a consolidated mass on or in the filter medium subject to limited analysis.
It is an object of the present invention, therefore, to provide a process and apparatus for separating magnetically responsive particles from a machine lubrication oil independently of non-magnetic particles.
Another object of the present invention is a small, portable apparatus for effectively separating magnetic particles from an oil sample and from other, non-magnetic, particles.
A still further object of the present invention is to provide a rapid and highly accurate field analysis method for machine lubrication oil.